Simplified calibration and analysis on screen-printed disposable platforms for electrochemical magnetic bead-based immunosensing of zearalenone in baby food samples.

An electrochemical immunosensor involving magnetic beads and disposable carbon screen-printed electrodes (SPEs) for zearalenone (Zea) sensing has been developed and evaluated using a certified reference material (CRM) and selected baby food samples. After the immunochemical reaction, the modified paramagnetic beads were confined by a magnet on surface of SPE platforms where electrochemical detection is simply achieved through the suitable substrate and mediator for the HRP enzyme. A remarkable detection limit of 0.007 microg L(-1) and excellent accuracy with recovery rate of 101-111% showed the proposed system to be a very suitable screening tool for the analysis of zearalenone in baby food samples. A new simple, fast and reliable strategy involving the sequential performing of calibration and analysis of target mycotoxin using just one disposable SPE each is additionally proposed. Excellent analytical performance in terms of accuracy and precision were again obtained with a remarkable low systematic error (less than 4%) and excellent reproducibility (RSD=6%). This strategy enhanced the analytical merits of immunosensor approach towards truly analytical disposable tools for food-safety scene.